Description
Memory safety bugs present in Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 144, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.
Affected products
mozilla: firefox; mozilla: thunderbird
References7
- www.mozilla.org/security/advisories/mfsa2025-81/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-83/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-84/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-85/ Vendor Advisory
- bugzilla.mozilla.org/buglist.cgi?bug_id=1983838%2C1987624%2C198… Broken LinkIssue Tracking
- lists.debian.org/debian-lts-announce/2025/10/msg00015.html
- lists.debian.org/debian-lts-announce/2025/10/msg00031.html
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 26 · as of 9 November 2026
- CWE
- CWE-119
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